(a) Field of the Invention
The present invention relates to a joint structure for coupling precast concrete pavement slabs, which is applied to pavement process in general.
(b) Description of Prior Art
In recent years, precast concrete pavement slabs have been widely employed for repairing or newly-paving a road, as it is advantageous both in its execution and abrasion resistance.
According to such prior execution process with the precast concrete pavement slabs, the pavement slabs laid on a road are coupled with one another by reinforcing bars, and then the rear faces of the pavement slabs are charged with filler material such as grout or the like.
A prior joint structure for coupling precast concrete pavement slabs is such that one end face of a first pavement slab is formed with one horizontal longitudinal hole (hereinafter one horizontal hole) for housing a reinforcing bar, while the other end face of a second pavement slab opposite to the first pavement slab is formed with the other longitudinal horizontal hole (hereinafter the other horizontal hole) for inserting nearly a distal half of the longitudinal length of the reinforcing bar. Then, the adjacent pavement slabs are mated and laid on a road with the reinforcing bar housed in one horizontal hole, and subsequently thereto, the reinforcing bar is slid toward the other horizontal hole. After that, filler such as grout or the like is charged into both horizontal holes for conjuction of the adjacent pavement slabs.
As a means for sliding the reinforcing bar, it has been known that an upper part of one horizontal hole is formed with an aperture, into which is inserted a hand to manually slide the reinforcing bar. Further, Japanese Patent Laid-Open No 58-7003 teaches that the reinforcing bar is slid by pushing its back by means of pressurized air or wires.
However, with the structure of the prior art having the aperture provided at an upper part of one horizontal hole, the reinforcing bar must be manually slid by an operator, thus resulting in low efficiency. Further, with another prior art such as sliding reinforcing bar by means of pressurized air or the like, packings or the like must be provided at the back of the reinforcing bar to transmit the force of the pressurized air thereto. In which case, in the event that the air-tightness between the packing and the horizontal hole is insufficient or low, the reinforcing bar cannot be slid well. Furthermore, according to the prior art, as the other horizontal hole for insertion of the distal half of the reinforcing bar must be formed to have a larger diameter than that of one horizontal hole, its casting process will inevitably become complicated, and such difference between the diameters can even cause the irregularity of the connection strength after having charged the holes with filler.
In addition, in case that there is a gap in position between the adjacent horizontal holes, the distal end of the reinforcing bar will strike on a peripheral edge of the other horizontal hole, thus preventing the bar from further advancing. In such a case, there have been some fear that filler will be charged by mistake with only a part of the distal portion of the reinforcing bar being inserted into the other horizontal hole.